The overall aim is to evaluate whether early therapy given for a limited time will improve HIV prognosis in the longer term by deferring the time that children need to start life-long ART. The primary objective compares time to failure of first line ART (due to clinical or immunological disease progression, or regimen-limiting ART toxicities) or death among three randomized arms (infants who receive early ART for a limited time in Arms 2 and 3 and infants in whom ART is deferred until clinical or immunological disease progression in Arm 1);the primary endpoint is time taken to reach the objective.